To enact his plan, on 1st August 1940, at Doenitz’s urging, the German naval high command authorised a total blockade of Britain, giving U-boat commanders the mandate to attack ships without warning or prior approval from superiors. Five years earlier Germany had signed a protocol barring this kind of unrestricted use of submarines as weapons of war, but the outbreak of war had, in Hitler’s view, nullified the agreement. International shipping law prohibited attacks on merchant ships, but Doenitz’s blunt battle orders that ‘fighting methods will never fail to be used merely because some
...more
